Prosthetic elements, such as prosthetic knee joints, artificial lower legs or artificial hands are attached to prosthesis sockets, which are situated on the relevant stump of the prosthetic user. According to the desired scope or function, there is a differentiation between purely cosmetic prostheses, mechanically activated prostheses and bioelectrically controlled prostheses. The relevant extremity to be replaced, or functional element to be provided, is typically located on the exterior socket, which is attached directly to the internal socket carried on the stump.
In myoelectrically powered prostheses, the conduction of an electrical action potential from the stump musculature is necessary. These potentials are emitted by the contraction of a muscle and are measurable on the skin surface of the prosthetic wearer. The potentials collected by an electrode are amplified and sent to the control unit, which activates or deactivates the actuators. The state of the art is to equip the internal socket with a recess or aperture in which the electrode can be inserted. Between the electrode and the recess in the internal socket there is a particular gap which can lead to a relative movement between the electrode and the internal socket. Through the gap between the internal socket and the electrode, perspiration can enter the space between the internal socket and the external socket, which can affect the electrical and electronic components. This can also make cleaning the internal socket difficult.